98 Subaru Overheating

subaru
outback

#1

My 98 Subaru only overheats when going above 60 mph for more than 10-15 minutes. When it does and I pull over,the cap has blown off of the coolant tank. After letting it cool off and adding a bit of coolant - it doesn’t occur again and I can drive for hours at high speeds. I drive the car every day, up and over mountain passes and up to the ski hill and never have a problem any other time. I know subarus have a tendency to blow head gaskets, but wouldn’t there be other warning signs? Any thoughts?


#2

It sounds like you may have a small leak. Have the coolant checked for traces of exhaust gases to see if that is the case.